1. Field of the Invention
The present invention relates to floating docks and, more particularly, to a modular floating dock system having an adjustable freeboard and a backup source of flotation.
2. Description of the Related Art
Although there are a large number and a wide variety of floating docks in present use, including both swimming docks and boat docks, nearly all of these floating docks are disadvantaged in one or more significant respects. For example, most floating docks rely on buoyant foam for floating the dock, even though the foam materials employed were not developed for this purpose. Using foam for floating a dock necessarily requires the foam to be immersed in water. When so immersed, the foam absorbs water and ultimately deteriorates, thereby requiring the foam to be periodically replaced--every six to eight years on average. In addition, beads or pieces of foam can break loose and pollute the marine environment. For this reason, recently promulgated regulations require the foam used in floating docks to be encapsulated. The encapsulated foam, however, costs as much as three times that of unencapsulated foam without overcoming many of the problems associated therewith. Since the encapsulation is typically not water-tight, the encapsulated foam still absorbs water in the same manner as unencapsulated foam. Consequently, encapsulated foam has the same perishable life as unencapsulated foam and must be periodically replaced, but at a significantly greater cost than in years past. For all of these reasons, the economies of floating docks using buoyant foams are suffering greatly.
Another problem associated with the various floating docks of the prior art is that the docks have no means for adjusting the level of flotation. As is well-known, the loads borne by a floating dock vary both seasonably and geographically as a result of snow, wind, and other conditions. The docks are ordinarily designed to have an amount of freeboard (i.e., the portion of the dock above the water level) complementary to the dock's intended use. For example, a floating boat dock is usually designed to have a freeboard sufficient to accommodate boats within a predetermined range of sizes. During winter months, however, this freeboard can be altered dramatically by snow loads which, in combination with a typical dock's insufficient strength, can result in a structural failure where the dock will first list and then collapse. Moreover, because most prior art docks are provided with only a single means for flotation, the docks will become submerged upon collapsing, thereby making retrieval or restoration of the dock unduly burdensome. Further still, it is well-known that the loads borne by different regions of a dock are seldom the same. Thus, even where a desired amount of freeboard is obtained for one region of the dock, the uneven loads can result in a different and undesirable amount of freeboard at a different region.
Still another problem with prior art docks relates to the manner in which the docks are constructed. The current construction approach is simply an accumulation of many independent systems in a non-integrated fashion. For example, a framework is usually constructed first for the flotation means. Another framework or subfloor is then constructed and attached to the framework for the flotation means, followed by the deck or floor itself. After electrical or plumbing utilities are installed, various covers or shields may then be constructed to conceal and protect the utilities. Thus, each functional component of the dock is independently constructed and then bolted or otherwise attached to the other components. Due to this primitive approach to dock construction, a needless amount of materials are employed, thereby rendering the dock excessively heavy and unnecessarily expensive. Further, the various dock components are oftentimes constructed and assembled in the same manner as static, land-based structures despite the dynamic conditions the dock will experience in use, thereby rendering the dock insufficiently strong. Further still, docks are commonly constructed with ordinary wood or steel components despite the highly corrosive nature of the dock environment. The prior art's cumbersome approach to dock construction also requires the dock to be constructed from the "ground up" at the desired dock site, even though constructing the dock in this environment, i.e., within a body of water, is far from convenient. Most prior art docks also have a rectangular shape with sharp corners that can seriously damage boats, for example, that collide with the sharp corners.
What is needed is a floating dock system having an integrated design which gives the dock a superior strength while using a minimum of materials, thereby reducing the cost and weight of the dock. Such a dock system should avoid the use of immersed foam materials, and should include a back-up source of flotation to prevent the dock from becoming submerged in the event of a failure. Such a floating dock system should also have an adjustable flotation, both for the dock as a whole as well as for individual regions thereof, so the freeboard of the dock can be adjusted for uneven or varying load conditions. The dock should be constructed of non-corrosive materials so as to increase the life of the dock and thus decrease its cost when averaged over the dock's useable life. Furthermore, such a floating dock system would ideally employ a modular design approach to permit manufacture of the modules on a large scale, off-site basis, thereby further reducing the cost of the dock. A modular approach would also simplify assembly of the dock at the desired dock location, and would allow multiple modules to be selectively assembled so as to yield a dock having any desired geometry.